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Biomedical subjects

W Li

Publications and source records attributed to W Li.

At least 1,225 records · Page 68Linked to original sources
PubMed1993

[Observation on the phenomenon of propagated sensation along meridians in youngsters].

That the opinion on the relation between the propagated sensation along meridians (PSM) and the age of the subjects was divergent in the results reported by some authors. In the last 10 years, we have performed a systematic investigation on PSM on a group of 536 youngsters. The main characteristics of PSM in youngsters were just the same as that of adults. However, the incidence of PSM in youngsters, particularly the degree of distinctness of PSM, was by far higher than that of adults. The results were stable and could be repeated in the experiments performed in different years. It showed that there was surely a close relation between the degree of distinctness of PSM and the age of subjects. This fact can not be appropriately explained at present. However, it provides an important clue to clarify the factors which influence the appearance of PSM, and in turn to promote the improvement of the therapeutic effect of acupuncture and cilacriation of the mechanism underlying the formation of PSM.

Acupuncture Therapy↗
PubMed1993

[Inductive differentiation effect of ginsenosides on human acute non-lymphocytic leukemic cells in 58 patients].

Ginsenosides are the main active component of Panax ginseng. It has been shown that ginsenosides have antineoplastic, antiaging, immunologic function enhancing and other pharmacological actions. In this article, result of experimental studies showed ginsenosides extracted from stem and leaf of Panax ginseng (GSL) has inductive differentiation effect on all types of acute nonlymphocytic leukemia cells in primary culture. The effect on M5, M4 was most potent, followed by M1, M2 and the least, on M3. Through analysis, it was considered that the inductive differentiation effect of ginsenosides might be due to the comprehensive effect of increasing intracellular cAMP and inducing interferon. Since GSL have some other important actions, therefore, if it could be used as a differentiation inducer in clinical practice or combined with other antineoplastic drugs, it would show co-antineoplastic actions in many aspect.

Adolescent↗
PubMed1993

[The physical properties, pharmacology and antifertility action of crystal trichosanthin protein liposome].

The crystal trichosanthin protein liposome (TPL) was prepared by an emulsion-forming method. The rate of entrapment was 33.0-44.8% and the rate of recovery was 95.15-99.58%. The determination of trichosanthin protein was accomplished by spectrophotometry at 650 nm, thus eliminating completely the interference of lipids. The distribution of particle size of TPL was mainly in the range of 1-2 microns (96.9%). TPL was sterilized by 60Co radiation at 4 degrees C for 90 min and was stable when stored at 4 degrees C, 25 degrees C and 37 degrees C. The seepage rate of trichosanthin from the liposome was 15.22% after storage for 38 days at room temperature. Experiments showed that TPL had a slight allergic reaction, but was safe by hemolysis and coagulation tests. When the mice were given TPL ip 8 micrograms per animal 6 days after pregnancy, the rate of termination of early pregnancy was 83.3%. It thus appears that TPL can terminate early pregnancy in mice distinctly. This indicates that TPL may be expected to be developed into a new type of anti-early pregnancy preparation.

Abortion, Induced↗
PubMed1993

[The changes in free radical and prostaglandin metabolism in newborn infants with asphyxia].

Blood plasma thromboxane-B2 (TXB2) and 6-keto-PGF1 alpha levels were determined by radioimmunoassay technique during the first six to sixteen hours of life in 16 newborn infants with severe asphyxia, 18 newborn infants with mild asphyxia and 27 normal term neonates. Plasma lipid peroxidation (LPO) content was measured by TBA-colour-contrast method in 15 infants with severe asphyxia, 17 infants with mild asphyxia and 24 healthy term newborn infants. The results showed that blood plasma LPO, TXB2 and 6-keto-PGF1 alpha levels in infants suffering from severe asphyxia were higher than those in infants with mild asphyxia and normal infants (P < 0.01), but no significant difference was noted between the mild asphyxia group and normal control group (P > 0.01). These suggest that production of free radicals is increased and prostaglandin metabolism is triggered in the infants with severe asphyxia, that cerebral ischemia and hypoxia caused by asphyxia contributes to the augmented production of prostaglandins and free radicals, and that accumulation of free radicals and prostaglandin enhances brain damage and the metabolism of arachidonic acid appears to be an important source of the free radicals in infants with intrauterine asphyxia.

6-Ketoprostaglandin F1 alpha↗
PubMed1993

[Effect of qigong on blood pressure and life quality of essential hypertension patients].

56 essential hypertension patients (stages I, II) received Qigong from Mar, 1989 to Sept, 1991, pre- and post-treatment comparison of BP and life quality (LQ) indices revealed that (1) It could efficiently lower BP(P < 0.001). Stroke, congestive heart failure and acute myocardial infarction did not occur. No side effects were observed as well. (2) It could markedly improve LQ of hypertensive patients. LQ examinations showed that significant difference (P < 0.001) existed among LQ indices except dysfunction, which might be due to the selection of non-dysfunctional patients. LQ should be widely used in clinical practice and medical research.

Adult↗
PubMed1993

An epidemiological survey of deformities and disabilities among 14,257 cases of leprosy in 11 counties.

This study was planned and conducted in Yang Zhou Prefecture, covering 11 counties that were formerly areas with a high prevalence of leprosy. Out of 14,257 leprosy patients, 8122 (56.97%) cases with deformities and disabilities were found. The disability rate is much higher in patients with MB leprosy (81.15%) than in PB leprosy (53.04%). The statistical data and the type of deformities and disabilities are presented. The influences of various host factors and disease factor which cause disability and deformity are discussed.

Adolescent↗
PubMed1993

[Long-term follow up of trigeminal neuralgic patients treated by retrogasserian rhizotomy or by microvascular decompression].

The authors studied the long-term follow up of trigeminal neuralgic patients treated by retrogasserian rhizotomy with anhydrous glycerol injection (GI) or by microvascular decompression (MVD) and compared the satisfaction rates between them. Since 1983, 67 patients had been treated either by GI or MVD. The authors analyzed the results of the treatment by the method of questionnaire. Fifty-two patients of these 67 answered the questions, on which the present analysis was based. GI group consisted of 27 patients and MVD group 29 patients. The average follow-up period was 30.9 months in GI group (maximum follow-up: 84 months) and 50.9 months in MVD group (maximum follow-up: 95 months), respectively. The technique of GI used was Härtel's method with cisternography of Meckel's cave. The operations of MVD were performed by J.H. and A.K.. One patient out of 29 failed to be treated by MVD and two recurred within one year. On the other hand, 2 patients out of 27 failed to be treated by GI and 11 recurred. The recurrence was seen earlier in patients who had undergone GI, while one patient recurred the neuralgia at 76 months later. The recurrence rate in patients treated by MVD is 7.0% at 95 months, while that by GI is 49.0% at 84 months based on Kaplan-Meier survival analysis. The pathogenesis of trigeminal neuralgia is speculated to be an emphatic conduction caused by segmental demyelination and artificial synapse formation at the junction of central and peripheral myelin. The factors of this demyelination may be multiple sclerosis, basilar impression, aneurysm, arteriovenous malformation, atheroscleroses and natural aging.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Therapeutic strategies distinguish community based primary care physicians from rheumatologists in the management of osteoarthritis.

Using an osteoarthritis (OA) case study, we described the drug therapy that primary care physicians prescribe for uncomplicated OA of the hip, and for OA complicated by a history of gastropathy or renal insufficiency. To produce "gold standard" criteria against which to interpret previous results, the same instrument was administered to 126 rheumatologists selected at random from the membership of the American College of Rheumatology. Virtually all rheumatologists prescribed nonsteroidal antiinflammatory drugs (NSAID); 76% specified doses large enough to have significant antiinflammatory effects. In contrast, 65% of the primary care physicians recommended NSAID therapy in a suboptimal antiinflammatory dose (p = 0.055 for the rheumatologist-primary care physician difference). For OA complicated by a history of either gastropathy or renal insufficiency, rheumatologists were more likely than primary care physicians to adopt a therapeutic strategy that did not inhibit prostaglandin synthesis (p < 0.001 for both). Differences also were noted in the ancillary therapies employed by the 2 groups for managing uncomplicated OA. Educational interactions between rheumatologists and primary care physicians could benefit by recognition of the differing perspectives on NSAID dosing, the avoidance of NSAID induced side effects, and ancillary therapies that appear to differentiate subspecialists and generalists.

Aged↗
PubMed1993

Colonic neoplasia in asymptomatic persons with negative fecal occult blood tests: influence of age, gender, and family history.

Six hundred twenty-one asymptomatic persons with negative fecal occult blood tests (ages 50-75 yr), including 496 with no known risk factors for colorectal cancer and 125 with a single first-degree relative with a history of colonic neoplasia developed after age 40, underwent screening colonoscopy. Three Dukes A cancers were detected in average-risk persons. The overall prevalence of adenomatous polyps was 27%. Multiple logistic regression analysis revealed that increasing age and male gender were both strong predictors of colonic neoplasia (p < 0.001). A positive family history of a single first-degree relative with colorectal cancer was not associated with an increased prevalence of colonic neoplasia (p = 0.29), although an effect may be present if the relative was < 60 yr at diagnosis. Overall 16% of males and 7% of women > or = 60 yr had at least one adenoma that was large (> or = 1 cm in size), villous or tubulovillous, or had grade 3 dysplasia. We conclude that the prevalence of colonic neoplasia in asymptomatic persons with negative fecal occult blood tests is substantial, particularly in elderly males. A family history of a single first-degree relative diagnosed at age > or = 60 yr with colorectal cancer is not associated with an increased prevalence of colonic adenomas.

Adenoma↗
PubMed1992

DNA correlations.

Explore the source record for details and available documents.

Base Sequence↗
PubMed1992

Association of the Shc and Grb2/Sem5 SH2-containing proteins is implicated in activation of the Ras pathway by tyrosine kinases.

The mammalian shc gene encodes two overlapping, widely expressed proteins of 46 and 52K, with a carboxy-terminal SH2 domain that binds activated growth factor receptors, and a more amino-terminal glycine/proline-rich region. These shc gene products (Shc) are transforming when overexpressed in fibroblasts. Shc proteins become phosphorylated on tyrosine in cells stimulated with a variety of growth factors, and in cells transformed by v-src (ref. 2), suggesting that they are tyrosine kinase targets that control a mitogenic signalling pathway. Here we report that tyrosine-phosphorylated Shc proteins form a specific complex with a non-phosphorylated 23K polypeptide encoded by the grb2/sem-5 gene. The grb2/sem-5 gene product itself contains an SH2 domain, which mediates binding to Shc, and is implicated in activation of the Ras guanine nucleotide-binding protein by tyrosine kinases in both Caenorhabditis elegans and mammalian cells. Consistent with a role in signalling through Ras, shc overexpression induced Ras-dependent neurite outgrowth in PC12 cells. These results suggest that Shc tyrosine phosphorylation can couple tyrosine kinases to Grb2/Sem-5, through formation of a Shc-Grb2/Sem-5 complex, and thereby regulate the mammalian Ras signalling pathway.

Adaptor Proteins, Signal Transducing↗
PubMed1992

Reconstitution, identification, purification, and immunological characterization of the 110-kDa Na+/Ca2+ antiporter from beef heart mitochondria.

The mitochondrial Na+/Ca2+ antiporter plays a key role in the physiological regulation of intramitochondrial Ca2+, which in turn attunes mitochondrial enzymes to the changing demands of the cell for ATP. We have now purified the Na+/Ca2+ antiporter from beef heart mitochondria by assaying detergent-solubilized chromatography fractions for reconstitutive activity. Na+ and Ca2+ transport were assayed using the fluorescent probes, sodium-binding benzofuran isophthalate and Fura-2, respectively. This approach enabled us to identify Na+/Ca2+ exchange activity with a 110-kDa inner membrane protein that catalyzed Na(+)-dependent Ca2+ transport and Ca(2+)-dependent Na+ transport. A new finding was that the Na+/Ca2+ antiporter also catalyzed Na+/Li+ exchange in the absence of Ca2+. All modes of transport were electroneutral and were inhibited by diltiazem and tetraphenylphosphonium cation. Monospecific polyclonal antibodies to the 110-kDa protein inhibited Na+/Ca2+ and Na+/Li+ exchange in the reconstituted system and recognized 110-kDa proteins in mitochondrial membranes isolated from rat heart, liver, and kidney.

Animals↗
PubMed1992

Rapid and sensitive anion-exchange high-performance liquid chromatographic determination of radiolabeled inositol phosphates and inositol trisphosphate isomers in cellular systems.

A rapid and sensitive high-performance liquid chromatographic method for the determination of multiple inositol phosphates and inositol trisphosphate isomers was developed. The separation of inositol phosphates was optimized by controlling the ionic strength with stepped gradient programs and the pH of mobile phase. Six inositol phosphates were determined within 22 min or the six compounds plus an inositol trisphosphate isomer within 24 min using a single anion-exchange column containing the quaternary ammonium functional group. This technique was successfully applied to the determination of inositol phosphatide turnover by AlF4-stimulation in a small amount (5.10(5)-1.10(6) cells) of cultured retinal capillary pericytes. Because of its efficiency, accuracy and applicability to the separation of inositol phosphates from biological samples, this method may be useful in signal transduction studies in cellular systems.

Animals↗
PubMed1992

Point mutation in FGF receptor eliminates phosphatidylinositol hydrolysis without affecting mitogenesis.

Stimulation of growth factor receptors with tyrosine kinase activity is followed by rapid receptor dimerization, tyrosine autophosphorylation and phosphorylation of signalling molecules such as phospholipase C gamma (PLC gamma) and the ras GTPase-activating protein. PLC gamma and GTPase-activating protein bind to specific tyrosine-phosphorylated regions in growth factor receptors through their src-homologous SH2 domains. Growth factor-induced tyrosine phosphorylation of PLC gamma is essential for stimulation of phosphatidylinositol hydrolysis in vitro and in vivo. We have shown that a short phosphorylated peptide containing tyrosine at position 766 from a conserved region of the fibroblast growth factor (FGF) receptor is a binding site for the SH2 domain of PLC gamma (ref. 8). Here we show that an FGF receptor point mutant in which Tyr 766 is replaced by a phenylalanine residue (Y766F) is unable to associate with and tyrosine-phosphorylate PLC gamma or to stimulate hydrolysis of phosphatidylinositol. Nevertheless, the Y766F FGF receptor mutant can be autophosphorylated, and can phosphorylate several cellular proteins and stimulate DNA synthesis. Our data show that phosphorylation of the conserved Tyr 766 of the FGF receptor is essential for phosphorylation of PLC gamma and for hydrolysis of phosphatidylinositol, but that elimination of this hydrolysis does not affect FGF-induced mitogenesis.

Animals↗
PubMed1992

The SH2 and SH3 domain-containing protein GRB2 links receptor tyrosine kinases to ras signaling.

A cDNA clone encoding a novel, widely expressed protein (called growth factor receptor-bound protein 2 or GRB2) containing one src homology 2 (SH2) domain and two SH3 domains was isolated. Immunoblotting experiments indicate that GRB2 associates with tyrosine-phosphorylated epidermal growth factor receptors (EGFRs) and platelet-derived growth factor receptors (PDGFRs) via its SH2 domain. Interestingly, GRB2 exhibits striking structural and functional homology to the C. elegans protein sem-5. It has been shown that sem-5 and two other genes called let-23 (EGFR like) and let-60 (ras like) lie along the same signal transduction pathway controlling C. elegans vulval induction. To examine whether GRB2 is also a component of ras signaling in mammalian cells, microinjection studies were performed. While injection of GRB2 or H-ras proteins alone into quiescent rat fibroblasts did not have mitogenic effect, microinjection of GRB2 together with H-ras protein stimulated DNA synthesis. These results suggest that GRB2/sem-5 plays a crucial role in a highly conserved mechanism for growth factor control of ras signaling.

Adaptor Proteins, Signal Transducing↗